472 HEALTH AND DISEASE 



volume of, or drying up, the phlegm which is a troublesome symptom 

 of chronic bronchitis. 



REMEDIES WHICH RELIEVE SPASM OF THE AIR-PASSAGES 



AND COUGH 



These, with our equine patients, are rather of a dietetic than medi- 

 cinal order, although what may be called artificial aid is given by drugs 

 in the alleviation of the spasmodic cough of chronic asthma or broken 

 wind (see p. 11 of this volume). The chief of them are: arseniates of 

 iron and copper, oils, fats, as suet and lard, and the sedative agents 

 already referred to, namely, opium, belladonna, camphor, conium, lobelia, 

 dulcamara, &c. 



To enumerate all the drugs which act directly or indirectly upon the 

 skin, when applied externally or administered internally, would be to 

 name many of the agents in the Pharmacopoeia. It will be understood, 

 therefore, that this title is given to such as have a special or marked 

 action upon the integument of the particular animal under consideration. 



In the portion of this work dealing with the physiology of the skin, 

 the great difference between human skin and that of the horse has been 

 alluded to. 



While the administration of certain drugs may be depended upon to 

 have an almost certain effect in producing sweating in man, no such pro- 

 nounced effect is seen in horses. " There is no drug ", says Col. Smith, 

 who has investigated the subject very thoroughly, " which produces 

 sweating in horses." It must be understood, however, that this remark 

 applies to visible perspiration. We cannot well believe that the insensible 

 perspiration which is always going on is not materially influenced by drugs 

 whose action upon the general condition of the skin has been well known 

 to practical horsemen for ages. (See Alteratives.) 



The importance of drugs acting upon the skin when externally applied 

 is frequently alluded to in other chapters, as when blisters are applied over 

 the seat of inflamed organs and parts of the body suffering from various 

 forms of injury. 



Drugs which are believed to increase the amount of sweat are called 

 sudorifics or diaphoretics. Among them may be mentioned, as being most 

 in favour with veterinary practitioners, acetate of ammonia, bicarbonates 

 of potash and soda, camphor, ipecacuanha, antimony, and Dover's powder, 

 which is a combination of opium, ipecacuanha, and potash sulphate. 



